how to merge asset source lines via spreadsheet

Summary:

Content (please ensure you mask any confidential information):

We have two requirements related to merge lines:

• Ability to merge lines interfaced from AP via spreadsheet: For Ex: there are ten line that users wants to merge to 1 line we can do the same via UI but how we can do the same via spreadsheet is the ask here
• Ability to auto merge freight lines in the invoice to the main: Currently all the lines in invoice are interfaced to FA as individual lines whereas the ask here is to auto merge freight lines in the invoice to the main line. Is there a way to achieve this ?